Entropy Theory and its Application in Environmental and Water Engineering responds to the need for a book that deals with basic concepts of entropy theory from a hydrologic and water engineering ...perspective and then for a book that deals with applications of these concepts to a range of water engineering problems. The range of applications of entropy is constantly expanding and new areas finding a use for the theory are continually emerging. The applications of concepts and techniques vary across different subject areas and this book aims to relate them directly to practical problems of environmental and water engineering.The book presents and explains the Principle of Maximum Entropy (POME) and the Principle of Minimum Cross Entropy (POMCE) and their applications to different types of probability distributions. Spatial and inverse spatial entropy are important for urban planning and are presented with clarity. Maximum entropy spectral analysis and minimum cross entropy spectral analysis are powerful techniques for addressing a variety of problems faced by environmental and water scientists and engineers and are described here with illustrative examples.Giving a thorough introduction to the use of entropy to measure the unpredictability in environmental and water systems this book will add an essential statistical method to the toolkit of postgraduates, researchers and academic hydrologists, water resource managers, environmental scientists and engineers. It will also offer a valuable resource for professionals in the same areas, governmental organizations, private companies as well as students in earth sciences, civil and agricultural engineering, and agricultural and rangeland sciences. This book:Provides a thorough introduction to entropy for beginners and more experienced usersUses numerous examples to illustrate the applications of the theoretical principlesAllows the reader to apply entropy theory to the solution of practical problemsAssumes minimal existing mathematical knowledgeDiscusses the theory and its various aspects in both univariate and bivariate casesCovers newly expanding areas including neural networks from an entropy perspective and future developments.
The fluid flow in fracture porous media plays a significant role in the assessment of deep underground reservoirs, such as through CO2 sequestration, enhanced oil recovery, and geothermal energy ...development. Many methods have been employed—from laboratory experimentation to theoretical analysis and numerical simulations—and allowed for many useful conclusions. This Special Issue aims to report on the current advances related to this topic. This collection of 58 papers represents a wide variety of topics, including on granite permeability investigation, grouting, coal mining, roadway, and concrete, to name but a few. We sincerely hope that the papers published in this Special Issue will be an invaluable resource for our readers.
The fluid flow in fracture porous media plays a significant role in the assessment of deep underground reservoirs, such as through CO2 sequestration, enhanced oil recovery, and geothermal energy ...development. Many methods have been employed—from laboratory experimentation to theoretical analysis and numerical simulations—and allowed for many useful conclusions. This Special Issue aims to report on the current advances related to this topic. This collection of 58 papers represents a wide variety of topics, including on granite permeability investigation, grouting, coal mining, roadway, and concrete, to name but a few. We sincerely hope that the papers published in this Special Issue will be an invaluable resource for our readers.
The fate of tropical forests under future climate change is dependent on the capacity of their trees to adjust to drier conditions. The capacity of trees to withstand drought is likely to be ...determined by traits associated with their hydraulic systems. However, data on whether tropical trees can adjust hydraulic traits when experiencing drought remain rare. We measured plant hydraulic traits (e.g. hydraulic conductivity and embolism resistance) and plant hydraulic system status (e.g. leaf water potential, native embolism and safety margin) on >150 trees from 12 genera (36 species) and spanning a stem size range from 14 to 68 cm diameter at breast height at the world's only long‐running tropical forest drought experiment. Hydraulic traits showed no adjustment following 15 years of experimentally imposed moisture deficit. This failure to adjust resulted in these drought‐stressed trees experiencing significantly lower leaf water potentials, and higher, but variable, levels of native embolism in the branches. This result suggests that hydraulic damage caused by elevated levels of embolism is likely to be one of the key drivers of drought‐induced mortality following long‐term soil moisture deficit. We demonstrate that some hydraulic traits changed with tree size, however, the direction and magnitude of the change was controlled by taxonomic identity. Our results suggest that Amazonian trees, both small and large, have limited capacity to acclimate their hydraulic systems to future droughts, potentially making them more at risk of drought‐induced mortality.
The fate of tropical forests under future climate change is dependent on the capacity of their trees to adjust to drier conditions. Following 15 years of experimentally imposed moisture deficit, Amazon trees showed no adjustment in their hydraulic traits to moisture deficit. This failure to adjust resulted in these drought‐stressed trees experiencing significantly reduced water potential and increased hydraulic failure. Both, small and large trees equally, could not adapt to moisture deficit. Our results suggest Amazon trees have a limited capacity to adjust to future droughts.
A systematic methodology for the real-time improvement of the overall efficiency of applications using hydraulic servo-axes is presented. The proposed methodology introduces three modules: a ...hydraulic actuator load estimator, a hydraulic energy optimizer and a controlled hydraulic power supply; these are discussed at the theoretical and application level. The proposed approach reduces the power losses across the main elements of the hydraulic circuit, leading to high energy savings and introducing a new guideline on managing and controlling the servo hydraulic actuator. The methodology is applicable to any application using hydraulic servo-axis systems, and therefore it is not tailored to a particular field. Its performances have been evaluated in different industrial case studies (a blanking press, a drawing press and a die-casting plant) through numerical simulations. Conspicuous energy savings, ranging between 59% and 88%, have been obtained in simulation, suggesting that a significant carbon footprint reduction for energy-intensive hydraulic machinery is achievable in a wide range of applications.
•Systematic methodology for the real time improvement of the overall efficiency of a hydraulic servo-axis.•Reduction of the power losses across the main elements of the hydraulic circuit, leading to high energy savings.•High bandwidth controlled hydraulic power supply.•The methodology applies to any application using hydraulic servo-axis systems, and therefore, it is not tailored to a particular field.•Its performances have been evaluated through numerical simulations in different industrial case studies.
•A normalized CNN is constructed for fault diagnosis of hydraulic piston pump.•Multiple signals are analyzed and used for intelligent fault diagnosis.•Bayesian algorithm is introduced for automatic ...selection of hyperparameters.•Severity level of different failure and changeable conditions are discussed.•The BNCNN presents high accuracy and stability by experimental verification.
Hydraulic piston pump is known as one of the most critical parts in a typical hydraulic transmission system. It is imperative to probe into an accurate fault diagnosis method to guarantee the stability and reliability of the system. Due to the shortcomings of traditional methods, the development of artificial intelligence enlightens the intensive exploration for machinery fault diagnosis. In this research, a normalized convolutional neural network (NCNN) framework with batch normalization strategy is developed for feature extraction and fault identification. First, the batch normalization technology is introduced in the modeling to resolve the change of data distribution. Second, inspired by the intelligent algorithms, Bayesian algorithm is employed to automatically tune the model hyperparameters. The improved model is named BNCNN. Third, BNCNN is used for fault diagnosis based on synchrosqueesed wavelet transform. The experiments in a hydraulic piston pump are employed for the demonstration of the method. Moreover, the superior performance of the proposed method is validated by the contrastive analysis. The results reveal that BNCNN can accurately and steadily complete the fault classification of hydraulic pump.
• Efficient water transport from soil to leaves sustains stomatal opening and steady-state photosynthesis. The aboveground portion of this pathway is well-described, yet the roots and their ...connection with the soil are still poorly understood due to technical limitations.
• Here we used a novel rehydration technique to investigate changes in the hydraulic pathway between roots and soil and within the plant body as individual olive plants were subjected to a range of water stresses.
• Whole root hydraulic resistance (including the radial pathway from xylem to the soil–root interface) constituted 81% of the whole-plant resistance in unstressed plants, increasing to >95% under a moderate level of water stress. The decline in this whole root hydraulic conductance occurred in parallel with stomatal closure and contributed significantly to the reduction in canopy conductance according to a hydraulic model.
• Our results demonstrate that losses in root hydraulic conductance, mainly due to a disconnection from the soil during moderate water stress in olive plants, are profound and sufficient to induce stomatal closure before cavitation occurs. Future studies will determine whether this core regulatory role of root hydraulics exists more generally among diverse plant species.
Summary
In the stems of terrestrial vascular plants studied to date, the diameter of xylem water‐conducting conduits D widens predictably with distance from the stem tip L approximating D ∝ Lb, with ...b ≈ 0.2. Because conduit diameter is central for conductance, it is essential to understand the cause of this remarkably pervasive pattern. We give reason to suspect that tip‐to‐base conduit widening is an adaptation, favored by natural selection because widening helps minimize the increase in hydraulic resistance that would otherwise occur as an individual stem grows longer and conductive path length increases. Evidence consistent with adaptation includes optimality models that predict the 0.2 exponent. The fact that this prediction can be made with a simple model of a single capillary, omitting much biological detail, itself makes numerous important predictions, e.g. that pit resistance must scale isometrically with conduit resistance. The idea that tip‐to‐base conduit widening has a nonadaptive cause, with temperature, drought, or turgor limiting the conduit diameters that plants are able to produce, is less consistent with the data than an adaptive explanation. We identify empirical priorities for testing the cause of tip‐to‐base conduit widening and underscore the need to study plant hydraulic systems leaf to root as integrated wholes.
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